The present invention relates to sensor arrays and networks and, more particularly, to fault-tolerant communication methods for use with sensor arrays and networks.
Conventionally, single sensor systems have been used to save space and manufacturing cost. But they are not suitable for critical applications because a single sensor is inevitably affected by noise, refresh delay and other uncertainty issues and cannot guarantee to deliver accurate information all the time. Development of MEMS (Micro Electro Mechanical Systems) has enabled production of relatively large number of micro sensors at a low cost. Micro flow-sensors are one of the most common MEMS devices which have been developed in recent years. Distributed micro flow-sensor arrays and networks (DMFSA/N), built from collections of cooperating intelligent micro flow-sensor nodes, can improve the accuracy, timeliness, and reliability of systems. Sensors incorporated with dedicated signal processing functions are called intelligent sensors, or smart sensors. In this context, a micro flow-sensor array refers to a group of micro flow-sensors of the same type placed close together to measure the same variable of interest. Another possibility is to combine different types of sensors to measure different variables in the same array. Different groups of micro flow-sensor arrays can be distributed widely and selectively in the flow environment to form a micro flow-sensor network.
Due to the inherent constraints of sensors and other electronic components and the effects of flow environment, however, it is unrealistic to expect sensor nodes and the communication links to function properly all the time. Therefore, fault tolerance is an important part of the design of a DMFSA/N. However, a need remains for more effective and efficient fault-tolerant methods and systems.